From: Richard Henderson <richard.henderson@linaro.org>
To: "Alex Bennée" <alex.bennee@linaro.org>, qemu-devel@nongnu.org
Cc: peter.maydell@linaro.org
Subject: Re: [Qemu-devel] [PATCH 0/2] tcg: Fix launchpad 1824853
Date: Fri, 19 Apr 2019 15:38:59 -1000 [thread overview]
Message-ID: <b0d8bc0a-cd4a-ed3a-a1ce-aeb8d5ce5ec0@linaro.org> (raw)
In-Reply-To: <87zholfvcb.fsf@zen.linaroharston>
On 4/19/19 1:07 PM, Alex Bennée wrote:
>
> Richard Henderson <richard.henderson@linaro.org> writes:
>
>> This is a case where we generate more than 64k code for a mere 231
>> guest instructions.
>
> I would like to know more! Are these unrolled vector ops or something else?
Yes. E.g.
ld4 { v0.16b - v3.16b }, [x0]
will generate 64 guest byte loads. Given the size of the code
generated for each guest memory operation, we should probably
change this to use 64-bit loads and dole out the bytes manually.
Even for linux-user, with direct host memory ops this converts
to 1k code.
r~
prev parent reply other threads:[~2019-04-20 1:39 UTC|newest]
Thread overview: 11+ messages / expand[flat|nested] mbox.gz Atom feed top
2019-04-16 8:31 [Qemu-devel] [PATCH 0/2] tcg: Fix launchpad 1824853 Richard Henderson
2019-04-16 8:31 ` [Qemu-devel] [PATCH 1/2] tcg: Hoist max_insns computation to tb_gen_code Richard Henderson
2019-04-19 21:01 ` Alistair Francis
2019-04-19 21:01 ` Alistair Francis
2019-04-16 8:31 ` [Qemu-devel] [PATCH 2/2] tcg: Restart after TB code generation overflow Richard Henderson
2019-04-16 17:47 ` Eric Blake
2019-04-16 17:55 ` Philippe Mathieu-Daudé
2019-04-16 18:48 ` Richard Henderson
2019-04-16 17:25 ` [Qemu-devel] [PATCH 0/2] tcg: Fix launchpad 1824853 Philippe Mathieu-Daudé
2019-04-19 23:07 ` Alex Bennée
2019-04-20 1:38 ` Richard Henderson [this message]
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